Lapping tool



April 29, 1930. vR. D. sTREBY 1,756,014

, LAPPING TooL Filed March. l1, 1929 2 Sheets-Sheet l u lll/1M April 29, 1930. R. D. sTREBY 1,756,014

LAPPING TOOL Patented Apr. 29, 1930 UNITED STATES PATENT oFFlcE y l BAY D. STREBY, OF CANTON, OHIO, ASSIGNOR TO THE TIMKEN BOEB BEARING COH- PANY, OF CANTON, OHIO, A CORPORATION OF OHIO LAPPING TOOL Application led Hatch 11, 1929. Seriallo. 845,941.

My invention' relates to lapping tools or ma chine attachments for lapping the inner or outer surface of annular articles such as cups and cones for roller bearings. It has for its principal object to producea slipping of the work with respect to the lapping member whereby the work is given an excellent finish. Further objects are the provision for selfalinement of the lapping tool (or tools) to accommodate itself to irregularitiesinthework,

yieldable means for holding the lapping tool against the work and providing different peripheral speeds for each of a pluraltly of lapping members. Further objects and advantages will appear hereinafter.

The invention consists princlpally 1n rotatably supporting each of a plurality of lapping members in a tubular head, pivotally mounting each of said heads in a supporting frame and arranging them in a circular series, providing spring devices for pressing the lapping tools against the work and giving each lapping member a peripheral speedv different from the speeds of the other lapping members, either by using lapping rolls of different sizes or by providing each lapping member with a special drive means giving it a dlii'erent speed of rotation from the speeds of the other lapping members. The invention further consists in the lapping tool and inthe parts and combinations and arrangements'of v Aparts hereinafter described and claimed.

In the accompanying drawing,

Fig. 1 is a longitudinal sectional view of a lappingtool embodying my invention, showing the device arranged to lap the inner surface of a roller bearing cup taken on vthe line 1*- -1 of Fig. 3; v

Fig. 2 is a side elevation;

Fig. 3 is a part t' p plan, part horizontal/ sectional view on th line 3-3 in Fig. 1; Fig. 4 is a diagrammatic end view of lapping rolls of three different sizes;

Fig. 5 isan enlarged sectional view of one of the lapping rolls; and ,v

Fig. 6 is a longitudinal sectional view of a sli htly modified form of the invention.

'supporting frame 1 is non-rotatably secured to a suitable machine having a rotary drive spindle 6 whose endportion extends through the central bore of said supportingframe. A cap 7 mounted on the end of said rotary spindle extends through a suitable bushing 8 in said frame and its projecting end has a gear 9 secured thereto. Said gear 9 meshes with all of a lurality of gears 10 (three being shown in t e draw ing). Each gear 10 is mounted on a spindle 11 that extends through a tubular support# ing member or hanger 12 that is provided with projecting trunnions 13 that are mounted in projecting arms 14 of said frame. Suitable bushings 15 are provided for both ends of said spindles 11 and lubricant cups 16 are provided therefor.

Each s indle 11 is provided with a shank port-ion 1 at its outer end'and each shank portion extends into the axial bore 18 of a lapping roll 19, the roll being secured to the shank 17 by means of a pin 20. Preferably, the end wall of each roll bore is formed into a l concave seat 21 and the tip of each shank 17 is correspondingly convexly curved, the bore 18 of each roll 19 tapers and the roll holes 22 through which the securing pins 20 pass are larger than said pins; so that each lapping roll is permitted a rocking or self-aligning.

pin between said nut and the supporting frame, a countersunk depression 26 being preferably provided in the frame to receive each spring 25. Thus said s rings 25 tend to force the outer ends of the hangers 12 (and hence the lapping rolls 19) radially outward so as to force the lapping rolls against the work.

The work, such as a bearing cup 27 or other annular member having a conical bore, is

mounted in a suitable support 28 that is free to rotate, but is not provided with a direct drive means.

In the lapping operation, the su rting frame 1 is moved eadwis'e se as to rmg which is pivotally secured a rod 36 that ex? i ferent speeds.

different surface or peripheral speed from the others. As all of the rolls are in enga ement with the surface of the work, the'wor is r0- tated as the result of the engagement of the rolls therewith, but slippage takes place as between the work and said rolls, the work being driven at any one time by only one roll and the other two rolls slipping. This slip- 'ping action produces the desired lapping of the work. Ordinaril some abrasive sub stance is used to assist 1n the lapping.

If desired, the supporting frame 1 may be reciprocated during the lapping operation; and the rolls 19 are free to accommodate themselves toany slight inaccuracies inthe surface of the work.

In the modified construction shown in Fig.

6, the gear 9 on the end of the drive spindle meshes with three gears 10, each having a different number of teeth; so that the lapping rolls 19 (which in this case may all be of the same size) are positively driven at dif- Said Fig. 6 discloses other features of construction that are somewhat different from the construction above described. The gears 10 are each secured to a short shaft 30' that is mounted in antifriction bearings 31 in the supporting frame 1.

Each4 lapping roll 19 is mounted on a pin 17 that is disposed in the end of a spindle 11 that is mounted in antifriction bearings 32 in a hanger 12': Said hanger is journaled at the bottom ofl said supporting frame l1. Said shaft 30 and spindle 11 are connected by an intermediate connecting member 33 that has swivel or universal joint connections 34 therewith, so as to accommodate the slight rocking movement of the lapping roll hangers 12 Without interfering with the drive of the lapping rolls. Each lapping roll hanger 12 has a projecting portion 35 to tends through a hole in the lower portion of the `supporting frame 1. On the threaded upper end of each rod 36 is a nut 37 and a coil spring 38 is mounted on the rod between i said nut and the supporting frame. The upward pressure of said spring tilts the hanger so as to force the lapping roll at the lower end thereof outwardly against the work. The movement of the hanger is limited (and adjusted) by means of a nut 39 threaded on the rod and adapted to engage theunden' side of the supporting frame.

Obviously the device is capable of lapping devices with cylindrical or other shaped bores and it may alsobe -arranged to lap the outer surface of annular articles. Numerous changes may be made without departing from the invention and do not wish to be limited to the precise cons ruction shown. f

What I claim is:

1. A lapping tool comprising, in combination, a supporting frame, a plurality of hangers pivotally supported on said. frame, a shaft rotatably m unted in each hanger, a lapping roll at the end of each shaft, s aid lapping rolls being conically disposed and arranged in a circular series whereby they are adapted to lap the inner surface of articles havlng a conical bore, spring devices engaging said hangers to force said lapping rolls against the work and means for rotatA ing said shafts.

2.` A lapping tool comprising, in combination, a supporting frame, a plurality of hangers pivotally supported on said frame, a shaft rotatably mounted in each hanger, a lapping roll at the end of each shaft, said rolls being so mounted on said shaft that they are free to rock to accommodate themselves to the work, said lapping rolls being conically disposed and arranged in a circular series whereby they, are adapted to lap the inner surface of articles having a conical bore,

spring devices engaging said hangers to force lapping rolls being conically disposed and i arranged in a circular series wherebythey are adapted to lap` the inner surface of articles having a conical bore, sprin devices engaging said hangers to force sai lapping rolls against the work, and a gear meshing with all of said first mentioned gears to drive them, said roll driving shafts having swivel joint portions intermediate their ends to accommodate swinging movement of said hangers without interfering with the drive ofthe roll shafts. Y

' :Signed at Canton, Ohio, this 6th day of March, 1929. Y

RAY D. STREBY. 

